Yes, but slower. Phase detect uses a separate sensor, and if that sensor or the optics in front of it are misaligned relative to the image sensor, focus will be off (and that why there's AFMA - to correct that misalignment). Contrast detect uses the image sensor itself to determine focus - nothing to misalign.

+1Contrast detect is not perfect, but so close that it doesn't matter. Its just slow. You can also chose the area you want to focus on by moving the white rectangle with your joystick (if there is one).It is a good way to check your phase detect AF, if live AF is sharp and phase detect is not, you need a adjustment. If neither are sharp, the issue might be more serious than a simple adjustment.

I think I am fine with center sharpness... however the corners are a bit worrisome... especially at 24 mm... this is supposedly the best 24mm canon has at corners... should I be concerned? I know I shot the "wall" but it is straight and plane

it looks to me that you have significantly more vignetting in the left side of the frame from that on the rightcould be your lens is decentered, I would take it back to the store and try another copy take those images with too to show them.

strange thing is this new version was supposed to fix decentering issues with the 24-70 that were common with the mk1

it looks to me that you have significantly more vignetting in the left side of the frame from that on the rightcould be your lens is decentered, I would take it back to the store and try another copy take those images with too to show them.

strange thing is this new version was supposed to fix decentering issues with the 24-70 that were common with the mk1

That could be my lighting set up... Let me try another shot with diffused daylight....

Yes, I'd go for a replacement, except that I'm just sitting back and seeing how everyone is doing with theirs. So far, I've read about a lot of sample variation, which is a bit disgusting. I'd consider the Tamron, except it seems to have even more issues with QC.Once you have found a good one, never let it go.